Arc lamp



Oct. 3, 1933. J. H. WAGENHORST ARC LAMP 4 Sheets-Sheet l Filed Oct. 15.1928 M ATTORNEY? Oct. 3, 1933.

J. H. WAGENHORST 1,929,295

ARC LAMP Filed 00 13, 1928 4 sheets-sheet 2 ZQV ATTORNEYS 4 Sheets-SheetI I l 2733 J. H. WAGENHORST ARC LAMP Filed Oct. 13, 1928 Oct. 3, 1933.

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F ,W HI W%W Oct. 3, 1933. J. H. WAGENHORST ARC LAMP Filed Oct. 13, 19284 Sheets-Sheet 4 v ilr fig; ATTORNEYS.

Patented Oct. 3, 1933 PATENT. o-FFI-ca I I ARC LAMP I James H'.Wagcnhorst, Jackson, Mich.

Application October s, 1928. Serial No. 312,326

14 Claims. (01; 176-58) -My. invention relates to improvements in arclamps and has to do, more particularly, with certain improvements in thedesign and construction of such lamps, which adapt them for use ingiving therapeutic treatments in the home. "The 1 present inventioncomprises certainimprovements over the arc lamps shownand'claimed in myPatents, Number 1,817,955, filed Marchd, 1926, and Number 1,884,417,flledJanJ 31, 1928.

The principal object of my invention is to pro- ,vide an arc lamp ofsuch construction asto be 1 very simple and efficient and which willoperate smoothly and effectively. Another object of my invention is toprovide an arc lamp construction in which all chattering due to the useof alternating current is eliminated. A further object of my inventionis to provide improved and simple means for retarding the movement ofthe electrodes, in the direction to'draw the arc, while leaving theelectrodes free to move toward each other when the arc has beenextinguished. 'Another object of my invention is to provide an improvedmeans by which the electrodes can be straightened and alined, after theyhave been clamped in the electrode holders. A further object of myinvention is to provide an arc lamp construction which will have agreater effective light output due to the f act that the crater of thearc is exposed so' that both the flame and the spot of the are areeffective. A further object of my invention is to provide an improvedcabinet construction and, further, a cabinet provided with means forpreventing sparks from falling from the cabinetto the floor of the roomin which the lamp is used. I I

- Further objects, and objects relating to details and economies ofconstruction and operation will definitely appear from the detaileddescription to follow. In one instance, I accomplish the objects of myvinvention by the devices and means set forth in the followingspecification. My invention is clearly out in the appended claims. Astructure constituting a preferred embodiment of my invention isillustrated in the accompanying drawings, forming a part of thisspecification, in which Figure 1 is:a perspective view of an arc lampembodying my invention;

Fig- 2 is a view of the lamp and operating mechanism in front elevation,a portion of the ing shown in section;

Fig. 3 is" a detail, sectional view, taken on the .line Ii-3 of Fig. 2;

defined and pointed Fig. 4 is a detail, sectional view taken on theline44of Fig.2;

Fig. 5 is a top plan view of the lamp, with the housing surrounding theoperating 'mechanism shown in section;

Fig. 6 is a detail, sectional view through the holder for the upperelectrodes, taken on the line 6-6 of Fig. 2; i

Fig. '7' is a detail, sectional 'view showing the connections betweenthe upper end of the clutchoperat-ing rod and the clutch-operating levertakenon the line 7-7 of Fig. 2;

Fig. 8 is a detail, sectional view showing the mounting for the-lowerelectrodes, taken on the line 8-8 of Fig. 2;

Fig. 9 is a wiring diagram showing the electrical connections for thelamp;

Fig. 10 isa detail, sectional view showing the means for holding theadjustable reflector or front wall of th'e'cabinet in adjusted position,and

Fig. 11 Ba detailed perspective view showin the clutch. I

In the drawings, the same reference nimerals refer to the same partsthroughout the several views andthe sectional views are taken looking inthe direction of the arrows at the ends of the section lines.

One of the objects of my invention is to eliminate the chattering of theelectrodes due to the use of alternating current and I accomplish thisobjectby providing a resilient support for the solenoid, the solenoidbeing supported by spring arms carried by'the frame. I have provided abrake for "retarding the movement of the operating mechanism which drawsthe arc, so as to slow up this movement. I have found that this brake issimpler than a dash-pot and that it has the advantage that it retardsmovement only in" the one direction. I have provided a saddle swiveledon one of the electrode holders and have found that this permits thecarbons or electrodes to be straightened and lined up after they havebeen clamped in theholders. My invention comprises also the mounting ofthe electrodes in the frame, and the suspension of the frame, in such away that the electrodes are inclined slightly from the vertical and leanbackward. 'I have found that this exposesthe crater of the arc, so thatboth the flame and the spot of the are are effective to give light. Ihave also provided an improved and simple cabinet construction as willbe seen hereinafter. I

Referring to'the particular embodiment of my invention illustrated inthe accompanying drawin the guide brackets33.

of which are suspended and supported from a frame 10, which is formedfrom a. bar or strip bent into rectangular form and provided with twoparallel tail members 11 extending from the central portion of the baseof the rectangular frame. These tail members 11 serve to support thelower or stationary electrodes of the arc lamp. A block 12, ofinsulating material, is fastened to these tail members 11 by bolts 13,and an electrode supporting bar 14 is fastened to the block 11 by thebolts 15. The bar 14 extends transversely of the lower portion of thelamp within the cabinet and has, at opposite ends, a pair of grooves 16,which are adapted to receive the electrodes 17. The electrodes areclamped in position on this bar by the clamping plates 18 and the bolts19, as shown more particularly in Fig. 8. In this way, the lower orstationary electrodes are so mounted that four of them can be clampedsubstantially parallel to each other. Referring toFig. 8, it will beseenthat the radius of each groove 16 is considerably less than the radius.of the carbon 17. Byv using grooves of this formation, I can clampcarbons of varying diameter in the same holders. This is of advantagebecause differences in current used sometimes require a slight variationin the size of the carbons employed. 7

To each side member of the frame 10, there are fastened slabs 20 ofinsulating material and, at the bottom, near the lower ends of theseslabs, the angle brackets 21 are fastened. These brackets havehorizontal legs provided with openings through which the movableelectrodes 22 extend. These movable electrodes, as well as thecorresponding stationary electrodes, are arranged in pairs, one pair oneach side of the center of the lamp. Each pair-of movable electrodes-22co-operates with an electrode holder comprising a plate 23, having, atone side, a groove 24 receiving one of the electrodes 22, while theother part of the plate is offset at 26, and h a-saddle 25 swiveledthereto by rivet 26, which saddle receives the other electrode. Theelectrodes are clamped in this holder by clamping plate 29,- whichengages the opposite sides of the electrodes and is clamped against theholder by bolt 30. The groove 24 and the saddle 25 are formed, as in thecase of the, lower carbons, so as to permit of the clamping ofelectrodes of varying diameter in the same holders. An angle bracket 27the upper end of which is bent laterally M33 and has an openingtherethrough through which the clutch' operating rod moves, is fastenedto the holder by bolt 30, washers 28; of insulating material, beingmounted on the bolt on opposite sides of the bracket 27 to insulate thesame from the carbon holder. The guiding brackets 33 which slide on theclutch operating rod 34, insure the accurate alinement of the upper andlower electrodes. These electrodes are guided at the points where theypass through the bracket 21 and by the sliding contact of the rods 34with the edges of the openings These points are spaced a considerabledistance apart, as will be seen from Fig. 3. Of course, a considerableclearance has to be provided in the holesin the guide brackets 21, topermit the electrodes to slide through them easily and'this clearancehas the tendency to throw the upper electrodes out of alinement with thelower electrodes as they are fed downwardly. However, due to the guidearms 33, the guiding points are kept far enough apart .to insure truealinement of upper and lower sie etrodes at all points in their feed.The terminal 31 of circuit lead 32 may be inserted beneath the head ofthe bolt 30 in order to make electrical connection between this lead andthe electrode holder. There are two electrode holders of thisconstruction provided, one for each pair of the upper or movableelectrodes, and these holders hold the electrodes clamped in parallelrelation to each other. The saddle 25 permits a slight swiveling of theelectrode which is clamped in it and this permits the electrodes to bestraightened and alined more conveniently after they have been clampedin the electrode holder.

Each pair of movable electrodes is provided with a clutch andclutch-operating mechanism by which these electrodes may be raised andlowered with reference to the lower or stationary electrodes, in orderto draw an arc. Each clutch comprises a fiat strip bent into a U-shapedform having the bight 38 of the loop embracing one of the electrodes, soas to clamp the same when.

tilted, while the legs 38' of the clutch member lie on opposite sides ofthe other electrode. A clutch-operating rod 34 extends through the guidehole in the portion 33 of bracket 27 fastened to the electrode holder,and the lower end of this clutch rod is bent laterally, at 35, and thenagain, at right angles, at 36, to form a portion which extends throughboth legs 38' of the U- shaped clutch member and is held in place withrespect thereto by cotter pins 37. The clutch member lies just above andcooperates with the horizontal portion of the corresponding bracketmember 21, as clearly shown in Fig. 11. The upper end of each,clutch-operating rod 34 is connected by a swivel or pivot connectionwith one of the two clutch-operating levers 39. The inner ends 40 ofthese levers cross each other and the levers are pivoted on the sidemembers of the frame 10, at 41. The shape of the clutch-operating leversis best shown in Fig. 5, and it will be seen that each comprises a flatstrip bent into U-form and having one leg longer. than the other andconstituting the inner end of the lever which crosses the correspondinginner end of the other lever. .One of these longer legs is provided witha slot 54' in which a bolt 55', carried by the corresponding leg of theother lever, works in order to provide a pin and slot connection betweenthe crossing ends of the clutch-operating levers. In Fig; 7, I haveshown the connection between the upper end of a clutch-operating rod 34and the corresponding outer end of the clutch-operating lever 39. A nut42 is mounted on the upper end of the rod 34, and held in positionthereon by the lock nuts 44 threaded on the rod-34 above and below nut42, and the washers 43, of insulating material, interposed between thenut 42 and the lock nuts 44, so that the nut 42 is held adjustably fixedwith reference to the upper end of the clutch-operating rod 34. The nut42 is swiveled to the outer end of the operating lever, which straddlesit, by a cross pin 45, which extends through the nut and through thelegs of the operating lever, as shown in Fig. 7.

The clutch-operating levers 39 are controlled by a solenoid 46, which ismounted in a resilient manner within the rectangular frame 10. The

solenoid 46 is clamped between end plates 47,

which are held together by the clamping rods 48. The springs 49arefastened to the inner side of the side member of the frame 10, at 50,and have laterally extending spring arms 51 fastened to the ends of theend plates 47. These spring arms provide a resilient support ,for thesolenoid46. The 'laminatedcore 52, which works within the solenoid, :hasthe laminations divided and the end portions iturned laterally, ;aS .at'53, providing twooppositel-y extending arms-connected by coil springs'54 with the levers '39, theiupper ends of said springs 'being hookedinto the ilevers at '55. In this way, there is a resilient connec-- tionbetween :the .core and the clutch-operating levers and a resilientsupport for the solenoid, and-I :have found that this arrangement isvery effective to prevent chattering of the electrodes due tofluctuations in-the current-passing through the solenoid.

in -order to damp andcheck the movement of the clutch-operatingI-levers, when moving in a direction to draw the arc, I have provided,instead of thevusual dash-pot, .a "brake mechanism which '1 have foundparticularly effective for :this purpose. A brake shoe P56 is-.provided:with a pair of 'ears -7 straddling one side member of theframe and secured thereto by the pivot :pin 58. A 'facing59, ofbra'kingmaterial, is applied to this shoe. A brake strap :60 {cooperates withthis=brake shoe. 'The' lowenend-of this'lbrake strap is loosely embracedby a loop 61 mounted on a side enembe'r' of the frame. The*upper end :ofthe'brake strap hasan eye 62 to which is fastened one end of a link 63,the other end of said link beingturned laterally and ,=projectingthrough the legs of the corresponding operating .lever39. It willbe seenthat, with this arrangement,-when the operating levers are moved in adirection to draw the arc, that is, to lift the movable electrodes, thelink.63 will draw thebraking strap=60 into contact with the brakingmaterial 559 and retard the motion of the lever, while, when the leversmove in the other directionyto :permit the electrodes to approach eachother, the link 63 will cause the strap'to move away from 'thebrake shoeso that there will be no retardationof the corresponding movement of theoperating :levers. The wiring diagram illustrating the electricalconnections of the arc lamp is shown in Fig. 9. One :terminal to whichone of the main circuit wires is connected is shown 91: 66, and thisterminal is connected with the solenoid 46 by the connecting wire 65.From the other end of the solenoid-'46, a connecting wire 32 leads tothe electrode holder for the right "handpairof upper or movableelectrodes. The circuit leads from the terminal 66, therefore, throughthe .wire 65, solenoid-46, wire '32 and the right hand electrode 22 tothe corresponding lower electrode and, thence, by thebarl'i to the lefthandielectrode 1'7, the left hand upper electrode :and the left handelectrode holder, and, thence, through the wire 67 to arterminal 68. Theterminal 68 is connected to the lower end of a resistance coil 69mountedon the right hand block 20 of insulating material. "The upper end.ofthis coil is connected by wire "10 with -a:correspond-' ing coil '71mounted on theleft hand slab 20.0f insulating material, and the circuitis from the terminal 68, through the resistancecoils "'70 and '71 to theterminal 772, to which the-other main circuit wire 'is connected. itwill be observed, therefore, that, whenever the circuit just describedis closed, the solenoid .will .be energized to attract its armature anddepress the inner ends of the clutch-operating levers 39,-thus raisingthe carbons'and causing the movable electrodes to separate from thelower electrodes. Whenever this circuit is brokenyhowever, as by theextinguishment'of the arc'drawn between the upper and lower electrodes,the-solenoid will be (lb-energized and the weight .of the .suspendedelectrodes will cause the clutch-operating levers to lift the core 52and thus permit the upper electrodes to move into contact once more withthe lower electrodes to re-establish the circuit.

The particular frame arrangement and the mounting for the electrodes,and the operating mechanism therefor, are particularly advantageous,since they balance the lamp laterally .as well .as foreand aft, reducethe lampfssize, :and insure ibetter'and more uniform lighting. The frame10 constitutes the backbone of the lamp and is centrally located. Due:to the insulating block 12, the lower electrodes are mounted slightlyin frontof the frame 10. The insulating boards i20.afiord supports forthe brackets 21, through which the upper electrodes slide, in alinementwith the lower electrodes. These insulating boards 20 extend fore .andaft of the lamp and are so arranged with the resistance coils 69 and'llthereon that the heat from the resistance coils is baflled and preventedfrom reaching the solenoid 46, which is located between the twoinsulating boards. Cool air passing through the opening '97 in thehousing 86, which surrounds the operating parts, passes up aroundthesolenoid and the resistance coilsand out 'through'the openings 89.This frame -10not only acts as the backbone :of the lamp, but .alsosupports :the cabinet and the housing for the operating mechanism.Thetail member 11 of this frame extends downwardly through an opening inthe bottom wall of the reflector or cabinet and this projectinglowerendof the vtailmember ll may be inserted in a tubular .socket ,upona supporting stand, .so that the lamp may .be supported either from a-fioor.stand or from an overhead suspension, as hereinafter described.

Thelowerends of the upper electrodes 22 and the lowerlelectrodes .17:are located within ahousing 'l3, "the top wall of which is secured tothe lower portion of theframe 10 by the :bolts '74. Holesare provided inthe top wall of this housing through which the electrodes 22 and thetail members 1110f the frame-extend, the latter afiording a support forthe lower electrodes within the housing. This cabinet is .formed ofsuitable material andso shaped as .to serve ;as.a reflector for thelight developed by the are formed between the adjacent ends of the upperand lower electrodes. 'To'this end, the rear wall 'l5,=is suitablycurved along parabolic lines. The front edge of wall 751has aflange '76curved forwardly to forma trough, which catches any sparks falling uponthe bottom -.Wall .of the housing and prevents them falling from theopen front of the .cabinet :to the floor .of the room in which thelampis used. Theside walls 'l'lofthe housing are extended beyond the frontedges of the top .and bottom walls, as .best shown inFig. 3. The :frontof the housing is closedbyamovable front wall '78, having sidewalls 779connected thereto which overlap the side wall extensions '17. "The frontwall is adjustably fixed with reference to the housing, as by :thebrackets 80,secured to theside wall 79 by the rivets 8i, and havingportions 82 bent .back against the inner face of the side-wall '7'].Thumb screws :83 extending through the side walls 79 and the brackets80, serve to clamp the side wall '77 against the :turned back portion 82of .thebracket, and tohold the movable front wal1x78 in adjustedposition. By adjusting this rfront vwall 178 back and forth the lightemanating from the. arc can be directed as necessary in the use of thelamp. The front wall 78 is hinged to the housing by cars 84 at the rearupper end of the front wall, which are hinged to projecting ears on thehousing by the pivot bolts 85, as shown in Figure '1; The rear edge ofthe upper wall 78 is bentinwardly at 78' so as to provide a ventilatingslot at the top of the reflector or cabinet through which the hot airand fumes coming from the arcs may escape at thetop of the reflector.

This movable front wall 78 provides a cabinet having an opening ofvariable dimensions through which the light is directed; The directlight rays both from the craters of the upper electrodes as well as theflames of the arcs, are directed downwardly at an angle of about 45. Thecabinet is so designed that the reflected light emanating from theflames and craters of the arcs is directed through the main opening ofthe cabinet. The lower stationary portion reflects the light of thecraters throughthe main light outlet. The movable upper wall 78 of thereflector confines the light to a'variable area dependent on itsposition, so'that all the light can be concentrated on a small or largearea. Thus, a doctor can treat his patient without subjecting himself tothe intense rays of light, or a photographer can, by adjusting the frontwall 78, determine the area which he will illuminate with the lamp andthus secure the variable lighting effects much sought after in themodern photographic art. If it is desired to soften the light, forphotographic or other purposes, a diffusing screen may be arranged anddrawn tight over th open front end of the reflector cabinet. 4

The operating mechanism of the lamp is covered by a housing 86 mountedupon the top of the reflector, as shown in Figure 1. A saddle member 87is fastened by rivet 88 to the inner top surface of housing 86 andloosely embraces the top member of the frame 10. This saddle serves tocenter the housing 86 with reference to the operating mechanism andmakes sure that it is properly applied so as not to interfere with anyof the working parts. Angle brackets 90 are riveted to the housing 86near the bottom of the side walls thereof, as shown in Fig. 2. Thehorizontal portions of these brackets lie upon the top wall of thereflector '73. These horizontal portions of the brackets 90 are providedwith slots 91, which receive the bolts 92 by which the brackets 90 areclamped to the top wall of the reflector housing. Openings 89 in theupper corners of the housing 86 permit the circulation of air throughthe housing to cool the operating parts. This circulation is aided bythe opening 97 formed in the central lower front portion of housing 86,which also permits the suspending arm to pass to the outside of thehousing, as shown in Figure 1. A bar 93 is inserted between the tailmembers 11 of the frame and fastened in position there, as shown in Fig.2. This bar is offset forwardly, at 94, and then extends upwardly, at95, to form a suspending arm. A pulley 96 is fastened to the upper endof this arm, through which runs a cable by which the apparatus may besuspended from the ceiling or a supporting bracket. This suspending armis located at such an angle that, when the apparatus is suspended by apulley, as shown in Fig. 3, the electrodes will not be in true verticalalinement but will be alined in a plane tilted backward slightly fromthe vertical. The result of this is that a more efficient discharge oflight is secured in that the crater formed at the cooperating ends ofthe electrodes does not tend to hide any of the light emanating from thehot spot at the meeting ends of the electrodes. By tilting theelectrodes slightly from the vertical in this way, the crater is soformed that it opens slightly toward the front of the reflector housingand thereby the light is permitted to emanate directly from the craterthrough the open mouth of the housing and it is not concealed orinterrupted by the walls of the crater.

I am aware that the particular embodiment of my invention illustrated inthe accompanying drawings, and here described, may be variedconsiderably without departing from the spirit of my invention, and,therefore, I claim my invention broadly as indicated by the appendedclaims.

What I claim is:

1. In an arc lamp, the combination of a frame, a stationary electrodesupported by the frame, a movable electrode cooperating with thestationary electrode to form an arc, a solenoid, yokes clamped to thetop and bottom of said solenoid, a pair of coil springs carried by theframe and. each having a pair of laterally extending arms secured toopposite ends of the adjacent yoke to yieldingly support said solenoid,a movable core for said solenoid, a clutch cooperating with the movableelectrode and connections between said core and clutch.

2. In an arc lamp, the combination of a frame including a pair ofupright portions, a stationary electrode supported by the frame, amovable electrode cooperating with the stationary electrode to form anarc, a solenoid resiliently supported from one only of said uprightportions of the frame, a movable core for said solenoid, a clutchcooperating with the movable electrode, and connections between saidcore and clutch including a resilient link.

3. In an arc lamp, the combination of a stationary electrode, a movableelectrode cooperating therewith to form an arc, a clutch for saidmovable electrode, operating means for said clutch, a braking surface,and a brake member connected with said means and movable thereby intoand out of brakingengagement with said surface.

4. In an arc lamp, the combination of a stationary electrode, a movableelectrode cooperating therewith to form an arc, a clutch for saidmovable electrode, a clutch operating lever, a braking surface, and abrake member connected with said lever and movable thereby into and outof braking engagement with said surface.

5. In an arc lamp, the combination of a stationary electrode, a movableelectrode cooperating therewith to form an arc, a clutch for saidmovable electrode, a clutch operating lever, a braking surface, and abrake member connected with said lever and brought into brakingengagement with said surface when the lever is actuated to move themovable electrode and draw the arc.

6. In an arc lamp, the combination of a frame, a stationary electrode, amovable electrode, a clutch cooperating with said movable electrode, abraking surface mounted on the frame, a clutch operating lever pivotedon the frame, a brake member adapted to engage said surface, and a linkconnecting said member and said lever.

7. In an arc lamp, the combination of a frame, v

a stationary electrode, a movable electrode, a clutch cooperating withsaid movable electrode, a braking surface mounted on the frame, a clutchoperating lever pivoted on the frame, a rod connecting said lever andclutch, a brake member adapted to engagev said surface and a linkconnecting the upper end of said member and the lever between thelatters point of connection with the rod and its pivot.

8. In an arc lamp, the combination of a frame, a stationary electrode, amovable electrode, a clutch cooperating with the movable electrode, aclutch operating lever pivoted on the frame, actuating means connectedto the inner arm of said lever, arod connecting the outer arm of saidlever and-the clutch, a brake shoe mounted on the frame, a brake strapcooperating with the shoe, and a link connecting the upper end of saidstrap and the outer arm of said lever.

9. In an arc lamp, the combination of a frame, a stationary electrode, amovable electrode, a clutch cooperating with the movable electrode,

a'clutch operating lever pivoted on the frame,

. actuating means connected to the inner arm of said levena rodconnecting the outer arm of said lever and the clutch, a swiveled brakeshoe mounted on the frame,- a brake strap cooperating with the shoe, anda link connecting the upper end of said strap and the outer arm of saidlever.

10. .In an arc lamp, the combination of a frame, a stationary electrode,a movable electrode, a clutch cooperating with the movable electrode,

, a clutch operating lever pivoted on the frame,

actuating means connected to the inner arm of said lever, a rodconnecting the outer arm of said lever and the clutch, a brake shoehaving a pair of laterally extending flanges located on oppositesides ofa frame member, .a horizontal pin pivotally connecting said shoe to theframe and extending through said flang'es, friction material carried bythe base of said shoe, a brake strap cooperating with the frictionmaterial of said shoe, and a link connecting the upper end of said strapand the outer arm of said lever.

11. In an arc lamp, the combination of a frame,

"a stationary electrode, a movable electrode, a

, clutch cooperating with the movable electrode, a clutch-operatinglever pivoted on the frame, actuating means connected to the inner armof said lever, a rod connecting the outer arm of said lever and theclutch, a brake shoe mounted on the frame, a brake strap cooperatingwith the shoe, a link connecting the upper end of said'strap and theouter arm of said lever, and a yoke fixed to the frame and embracing thelower end of said strap.

12. In an arc lamp, the combination of a frame, a stationary electrode,a movable electrode, a clutch cooperating with the movable electrode, aclutch-operating lever pivoted on the frame, actuating means connectedto the inner arm of said lever, a rod connecting the outer arm of saidlever and the clutch, a swiveled brake shoe mounted on the frame, abrake strap cooperating with the shoe, and a link connecting the up perend of saidstrap and the outer arm of said lever, and a yoke fixed tothe frame and embrac ing the lower end of said strap.

13. In an arc lamp, the combination of a frame having a pair of uprightmembers, a pairof stationary electrodes, a pair of movable electrodes, apair of clutches cooperating therewith, a U shaped lever having a longand a short leg straddling, and pivoted to one upright frame member, theshort leg terminating adjacent the pivot, the long leg exending inwardlybeyond the pivot, a similar lever disposed upon the other uprightmember, the long leg of each lever being an alignment with the short legof the other lever, whereby the long legs of the levers are disposed inside by side relation, a link connecting the outer end of each lever toits respective clutch, a solenoid, a core for the solenoid, andconnections between said core and the long legs of the levers.

14. In an arc lamp, the combination of a frame including a pair ofupright portions, a stationary electrode supported by the frame, amovable electrode cooperating with the stationary electrode to form anare, a pair of spring arms carried by andextending laterally from one ofsaid upright portions of the frame, a solenoid inserted between andsupported by said arms whereby said solenoid is yieldingly supportedfrom the frame, a movable core for said solenoid, a clutch cooperatingwith the movable electrode and connections between said core and clutch.

JAMES H. WAGENHORST.

